Search

Sleep is essential to life. Accurate measurement and classification of sleep/wake and sleep stages is important in clinical studies for sleep disorder diagnoses and in the interpretation of data from consumer devices for monitoring physical and mental well-being. Existing non-polysomnography sleep classification techniques mainly rely on heuristic methods developed in relatively small cohorts. Thus, we aimed to establish the accuracy of wrist-worn accelerometers for sleep stage classification and subsequently describe the association between sleep duration and efficiency (proportion of total time asleep when in bed) with mortality outcomes. We developed a self-supervised deep neural network for sleep stage classification using concurrent laboratory-based polysomnography and accelerometry. After exclusion, 1113 participant nights of data were used for training. The difference between polysomnography and the model classifications on the external validation was 48.2 min (95% limits of agreement (LoA): −50.3 to 146.8 min) for total sleep duration, −17.1 min for REM duration (95% LoA: −56.7 to 91.0 min) and 31.1 min (95% LoA: −67.3 to 129.5 min) for NREM duration. The sleep classifier was deployed in the UK Biobank with ~100,000 participants to study the association of sleep duration and sleep efficiency with all-cause mortality. Among 66,262 UK Biobank participants, 1644 mortality events were observed. Short sleepers (<6 h) had a higher risk of mortality compared to participants with normal sleep duration 6–7.9 h, regardless of whether they had low sleep efficiency (Hazard ratios (HRs): 1.36; 95% confidence intervals (CIs): 1.18 to 1.58) or high sleep efficiency (HRs: 1.29; 95% CIs: 1.04–1.61). Deep-learning-based sleep classification using accelerometers has a fair to moderate agreement with polysomnography. Our findings suggest that having short overnight sleep confers mortality risk irrespective of sleep continuity. [ABSTRACT FROM AUTHOR]

As families increase their use of mobile touch screen devices (smartphones and tablet computers), there is potential for this use to influence parent-child interactions required to form a secure attachment during infancy, and thus future child developmental outcomes. Thirty families of infants (aged 9–15 months) were interviewed to explore how parents and infants use these devices, and how device use influenced parents' thoughts, feelings and behaviours towards their infant and other family interactions. Two-thirds of infants were routinely involved in family video calls and one-third used devices for other purposes. Parent and/or child device use served to both enhance connection and increase distraction between parents and infants and between other family members. Mechanisms for these influences are discussed. The findings highlight a new opportunity for how hardware and software should be designed and used to maximise benefits and reduce detriments of device use to optimise parent-infant attachment and child development. Practitioner Summary: Many families with infants regularly use smartphones and tablet computers. This qualitative study found that how devices were used either enhanced or disrupted feelings of parent-infant attachment. Practitioners should be aware of the potential beneficial and detrimental impacts of device use among families given implications for attachment and future child development. [ABSTRACT FROM AUTHOR]

To investigate: (1) whether TV watching habits throughout childhood and adolescence, a proxy of sedentary behaviour, impacted cardiorespiratory fitness (CRF) in adulthood, and (2) whether any potential impact of TV watching in childhood and adolescence on CRF in adulthood was changed by adult physical activity (PA) levels. A longitudinal study with questionnaire data available regarding TV watching collected at ages 5, 8, 10, 14, 17 and 20 yrs, allowed trajectories of TV watching to be developed. At age 28 yrs, participants completed a V̇O2peak test and the International Physical Activity Questionnaire. General linear models tested for differences in CRF (time to exhaustion TTE and V̇O2peak mL·kg−1·min−1) between TV watching trajectories. The secondary analysis tested the potential effect current PA levels has on the relationship between TV trajectory and fitness. In total, 449 participants [male n = 255 (56.8%), 28.3 ± 0.5 yrs; female n = 194 (43.2%), 28.2 ± 0.4 yrs] were included in the study. Three distinct trajectories of TV watching were identified: High TV, Increasing TV and Low TV. CRF was lowest in the High TV watching trajectory and increased progressively from High to Increasing TV and Increasing to Low TV (all P <.05). Within each of the TV trajectories, those engaging in high levels of current PA had greater CRF than those engaging in low and moderate PA. TV watching in childhood and adolescence negatively impacts upon adult fitness at the age of 28 years. However, this negative impact of historical TV watching on CRF can largely be attenuated by engaging in higher levels of PA in adulthood. [ABSTRACT FROM AUTHOR]

This study aimed to assess occupational health professionals' application of the Goldilocks Work Paradigm in redesigning jobs for healthier physical behaviours while maintaining productivity. During a group simulation exercise, participants (n = 16) created job descriptions for four different occupation cases (factory worker, office worker, teacher, train driver) and then redesigned the jobs using the Paradigm. Substantial changes in the time spent in sitting (9–30%), standing (8–42%), walking (6–14%), and high-intensity (0–24%) physical behaviours were achieved, which if implemented would likely result in enhanced health for workers. Overall, occupational health professionals were able to successfully redesign fictitious jobs aligned with the Goldilocks Work Paradigm. The simulation task used in this study may be useful to train professionals and assist workplaces to understand and implement the Goldilocks Work Paradigm into practice. Practitioner summary: This study assessed whether occupational health professionals could be trained in the Goldilocks Work Paradigm through a job redesign simulation task. Participants were able to redesign jobs to achieve a healthier 'just right' balance of physical behaviours. Simulations may help workplaces understand and implement a Goldilocks Work approach into practice. [ABSTRACT FROM AUTHOR]

Adolescent tennis players are at risk for low back pain (LBP). Recent research has demonstrated a potential mechanical etiology during serves; however, groundstrokes have also been suggested to load this region. Therefore, this study compared lumbar mechanics between players with and without a history of LBP during open and square stance tennis forehands and backhands. Nineteen elite, adolescent, male tennis players participated, 7 with a history of recurrent disabling LBP and 12 without. Differences in three-dimensional lumbar kinetics and kinematics were compared between pain/no pain groups and groundstrokes using linear mixed models (P < .01). There were no significant differences between pain/no pain groups. Relative to a right-handed player, groundstroke comparisons revealed that forehands had greater racquet velocity, greater lumbar right lateral flexion force, as well as upper lumbar extension/rightward rotation and lower lumbar right rotation/lateral flexion movements that were closer to or further beyond end of range than backhands. Backhands required upper lumbar leftward rotation that was beyond end range, while forehands did not. Given that players typically rotated near to their end of range during the backswing of both forehands and backhands, independent of pain, groundstrokes may contribute to the cumulative strain linked to LBP in tennis players. [ABSTRACT FROM AUTHOR]

Background: Neck pain is prevalent among office workers. This study evaluated the impact of an ergonomic and exercise training (EET) intervention and an ergonomic and health promotion (EHP) intervention on neck pain intensity among the All Workers and a subgroup of Neck Pain cases at baseline.Methods: A 12-month cluster-randomized trial was conducted in 14 public and private organisations. Office workers aged ≥18 years working ≥30 h per week (n = 740) received an individualised workstation ergonomic intervention, followed by 1:1 allocation to the EET group (neck-specific exercise training), or the EHP group (health promotion) for 12 weeks. Neck pain intensity (scale: 0-9) was recorded at baseline, 12 weeks, and 12 months. Participants with data at these three time points were included for analysis (n = 367). Intervention group differences were analysed using generalized estimating equation models on an intention-to-treat basis and adjusted for potential confounders. Subgroup analysis was performed on neck cases reporting pain ≥3 at baseline (n = 96).Results: The EET group demonstrated significantly greater reductions in neck pain intensity at 12 weeks compared to the EHP group for All Workers (EET: β = - 0.53 points 95% CI: - 0.84- - 0.22 [36%] and EHP: β = - 0.17 points 95% CI: - 0.47-0.13 [10.5%], p-value = 0.02) and the Neck Cases (EET: β = - 2.32 points 95% CI: - 3.09- - 1.56 [53%] and EHP: β = - 1.75 points 95% CI: - 2.35- - 1.16 [36%], p = 0.04). Reductions in pain intensity were not maintained at 12 months with no between-group differences observed in All Workers (EET: β = - 0.18, 95% CI: - 0.53-0.16 and EHP: β = - 0.14 points 95% CI: - 0.49-0.21, p = 0.53) or Neck Cases, although in both groups an overall reduction was found (EET: β = - 1.61 points 95% CI: - 2.36- - 0.89 and EHP: β = - 1.9 points 95% CI: - 2.59- - 1.20, p = 0.26).Conclusion: EET was more effective than EHP in reducing neck pain intensity in All Workers and Neck Cases immediately following the intervention period (12 weeks) but not at 12 months, with changes at 12 weeks reaching clinically meaningful thresholds for the Neck Cases. Findings suggest the need for continuation of exercise to maintain benefits in the longer term.Clinical Trial Registration: hACTRN12612001154897 Date of Registration: 31/10/2012. [ABSTRACT FROM AUTHOR]

Background: Accurate and detailed measurement of a dancer’s training volume is a key requirement to understanding the relationship between a dancer’s pain and training volume. Currently, no system capable of quantifying a dancer’s training volume, with respect to specific movement activities, exists. The application of machine learning models to wearable sensor data for human activity recognition in sport has previously been applied to cricket, tennis and rugby. Thus, the purpose of this study was to develop a human activity recognition system using wearable sensor data to accurately identify key ballet movements (jumping and lifting the leg). Our primary objective was to determine if machine learning can accurately identify key ballet movements during dance training. The secondary objective was to determine the influence of the location and number of sensors on accuracy. Results: Convolutional neural networks were applied to develop two models for every combination of six sensors (6, 5, 4, 3, etc.) with and without the inclusion of transition movements. At the first level of classification, including data from all sensors, without transitions, the model performed with 97.8% accuracy. The degree of accuracy reduced at the second (83.0%) and third (75.1%) levels of classification. The degree of accuracy reduced with inclusion of transitions, reduction in the number of sensors and various sensor combinations. Conclusion: The models developed were robust enough to identify jumping and leg lifting tasks in real-world exposures in dancers. The system provides a novel method for measuring dancer training volume through quantification of specific movement tasks. Such a system can be used to further understand the relationship between dancers’ pain and training volume and for athlete monitoring systems. Further, this provides a proof of concept which can be easily translated to other lower limb dominant sporting activities [ABSTRACT FROM AUTHOR]

BACKGROUND: This study sought to explore factors in adults with cystic fibrosis (CF) that predicted whether (i) someone was engaged in full-time paid work, and (ii) those engaged in paid work reported problems with absenteeism and/or presenteeism. METHODS: Adults with cystic fibrosis who live in Western Australia completed absenteeism and presenteeism questions from the World Health Organization's Health Performance Questionnaire. The participants were grouped by work status (full time vs part time or unemployed) and by self-reported absenteeism and presenteeism (evidence of vs no evidence of). We explored whether factors such as air-flow obstruction, level of education, health-related quality of life (measured by using the Cystic Fibrosis Questionnaire--Revised), and treatment adherence predicted group membership. RESULTS: Of the 50 participants for whom data were available (median [interquartile range] age 30 [25-36] y; mean ± SD FEV1% predicted, 60 ± 18%); 34 (68%) worked full time. A higher education level increased the odds of working full time (odds ratio 1.74, 95% CI 1.36-1.89). Among the employed participants, problems with absenteeism and presenteeism were reported by 20 (47%) and 7 (16%), respectively. Both those who reported problems with absenteeism or presenteeism were characterized only by lower scores on the role domain of the Cystic Fibrosis Questionnaire--Revised (P = .02). CONCLUSIONS: In this study, the majority of adults with cystic fibrosis worked full time and a low percentage of the sample reported problems with absenteeism and presenteeism. [ABSTRACT FROM AUTHOR]

* STUDY DESIGN: Prospective cohort study of the Western Australian Pregnancy Cohort (Raine) Study. * BACKGROUND: Low back pain (LBP) commonly develops in adolescence and is a significant risk factor for adult LBP. A broad range of factors have been associated with the development of adolescent LBP, but prior literature has limitations related to characterization of LBP and the scope of risk factors considered. * OBJECTIVE: This study aimed to identify potential factors contributing to the development of LBP, with and without impact, at 17 years of age, utilizing a broad range of exposures at 14 years of age. * METHODS: Data from 1088 participants (52,1% female) with "no LBP," "LBP with minimal impact," and "LBP with impact" at 17 years of age and a range of measures from multiple domains, including spinal pain, physical, psychological, social, and lifestyle, at 14 years of age were collected for the study. Multivariable multinomial logistic regression was used to estimate the association of potential mechanistic factors at 14 years of age with LBP at 17 years of age. * RESULTS: Female sex and back pain at 14 years of age were strongly associated with LBP at 17 years of age. Potential mechanistic factors for LBP outcomes at 17 years of age included exposures from the pain (neck/shoulder pain) and physical domains (standing posture subgroup membership, back muscle endurance, throwing distance), psychological domain (somatic complaints, aggressive behavior), social domain (socioeconomic area), and lifestyle domain (exercise out of school). * CONCLUSION: The findings support the multidimensional nature of adolescent LBP and highlight the challenge this presents for epidemiological research, clinical practice, and prevention initiatives in the general population. * LEVEL OF EVIDENCE: Prognosis, level lb. [ABSTRACT FROM AUTHOR]

Occupational falls are one of the leading causes of occupational injury and death internationally. This study described the nature of occupational falls following an analysis of workers compensation data in Western Australia. Frequencies, proportions and incidence rates were calculated following mechanism, gender, age and industry stratification. The natures of injury and bodily locations affected were compared between mechanisms of fall. Industry incidence rates were ranked and their corresponding proportions reported. Cost and lost time were described and risk scores for each burden type (incapacity, cost and lost time) were calculated and compared between fall mechanisms. Of all occupational falls, the proportion, incidence rates and risk scores of falls on same level were consistently greater compared to falls from a height. Gender, age and industry groups that appear to be at highest risk vary with the measure used and mechanism of incident. This study translates epidemiological information into a risk score that can aid in prioritisation. Practitioner Summary: This paper presents an in-depth analysis of Worker’s Compensation claims for falls in Western Australia. Calculated proportion, incidence rates and formulated risk scores for falls on the level were consistently greater compared to falls from a height. Limitations associated with the analysis of large-scale data-sets are described. [ABSTRACT FROM AUTHOR]

Objectives: To establish the inter-rater reliability of an observation-based ergonomics assessment checklist for computer workers.Methods: A 37-item (38-item if a laptop was part of the workstation) comprehensive observational ergonomics assessment checklist comparable to government guidelines and up to date with empirical evidence was developed. Two trained practitioners assessed full-time office workers performing their usual computer-based work and evaluated the suitability of workstations used. Practitioners assessed each participant consecutively. The order of assessors was randomised, and the second assessor was blinded to the findings of the first. Unadjusted kappa coefficients between the raters were obtained for the overall checklist and subsections that were formed from question-items relevant to specific workstation equipment.Results: Twenty-seven office workers were recruited. The inter-rater reliability between two trained practitioners achieved moderate to good reliability for all except one checklist component.Conclusions: This checklist has mostly moderate to good reliability between two trained practitioners. Practitioner Summary:This reliable ergonomics assessment checklist for computer workers was designed using accessible government guidelines and supplemented with up-to-date evidence. Employers in Queensland (Australia) can fulfil legislative requirements by using this reliable checklist to identify and subsequently address potential risk factors for work-related injury to provide a safe working environment. [ABSTRACT FROM AUTHOR]

Background. There is conflicting evidence on the association between sagittal neck posture and neck pain. Objective. The purposes of this study were: (1) to determine the existence of clusters of neck posture in a cohort of 17-year-olds and (2) to establish whether identified subgroups were associated with biopsychosocial factors and neck pain. Design. This was a cross-sectional study. Methods. The adolescents (N= 1,108) underwent 2-dimensional photographic postural assessment in a sitting position. One distance and 4 angular measurements of the head, neck, and thorax were calculated from photo-reflective markers placed on bony landmarks. Subgroups of sagittal sitting neck posture were determined by cluster analysis. Height and weight were measured, and lifestyle and psychological factors, neck pain, and headache were assessed by questionnaire. The associations among posture subgroups, neck pain, and other factors were evaluated using logistic regression. Results. Four distinct clusters of sitting neck posture were identified: upright, intermediate, slumped thorax/forward head, and erect thorax/forward head. Significant associations between cluster and sex, weight, and height were found. Participants classified as having slumped thorax/forward head posture were at higher odds of mild, moderate, or severe depression. Participants classified as having upright posture exercised more frequently. There was no significant difference in the odds of neck pain or headache across the clusters. Limitations. The results are specific to 17-year-olds and may not be applicable to adults. Conclusion. Meaningful sagittal sitting neck posture clusters were identified in 17-year-olds who demonstrated some differences with biopsychosocial profiling. The finding of no association between cluster membership and neck pain and headaches challenges widely held beliefs about the role of posture in adolescent neck pain. [ABSTRACT FROM AUTHOR]

Fitness is an important component of health, and obese adolescents regularly have poor fitness. Unfortunately, few have assessed the impact of community-based lifestyle interventions on multiple components of fitness. The purpose of this study was to assess the impact of participation in a community-based intervention involving adolescents and parents on multiple components of fitness of obese adolescents. In a within-subject, waitlist controlled clinical trial with 12 months follow-up in Western Australia, participants (n = 56) completed multiple fitness measures at baseline, immediately prior to beginning an 8-week intervention and at 3, 6 and 12 months during a maintenance period. Performance on the shuttle walk was improved immediately post-intervention (increase of 42.8 m, 95% CI: 7.5, 78.2) and at 12 months post-intervention (increase of 44.6 m, 95% CI: 1.3, 87.8) compared with pre-intervention. Muscle performance of quadriceps and deltoids were improved post-intervention (increase of 1.1 (95% CI: 0.1, 2.1) kg · F and 1.0 (0.02, 2.1) kg · F, respectively) and all muscle performance measures were improved at 12 months following the intervention. There were no changes in waist circumference. A community-based lifestyle programme such as Curtin University’s Activity, Food and Attitudes Program (CAFAP) may be a viable strategy for improving fitness in overweight adolescents. [ABSTRACT FROM AUTHOR]

Background: To provide a detailed description of young adults' sedentary time and physical activity. Methods: 384 young women and 389 young men aged 22.1 ± 0.6 years, all participants in the 22 year old follow-up of the Raine Study pregnancy cohort, wore Actigraph GT3X+ monitors on the hip for 24 h/day over a one-week period for at least one 'valid' day (≥10 h of waking wear time). Each minute epoch was classified as sedentary, light, moderate or vigorous intensity using 100 count and Freedson cut-points. Mixed models assessed hourly and daily variation; t-tests assessed gender differences. Results: The average (mean ± SD) waking wear time was 15.0 ± 1.6 h/day, of which 61.4 ± 10.1 % was spent sedentary, 34.6 ± 9.1 % in light-, 3.7 ± 5.3 % in moderate- and, 0.3 ± 0.6 % in vigorous-intensity activity. Average time spent in moderate to vigorous activity (MVPA) was 36.2 ± 27.5 min/day. Relative to men, women had higher sedentary time, but also higher vigorous activity time. The 'usual' bout duration of sedentary time was 11.8 ± 4.5 min in women and 11.7 ± 5.2 min in men. By contrast, other activities were accumulated in shorter bout durations. There was large variation by hour of the day and by day of the week in both sedentary time and MVPA. Evenings and Sundays through Wednesdays tended to be particularly sedentary and/or inactive. Conclusion: For these young adults, much of the waking day was spent sedentary and many participants were physically inactive (low levels of MVPA). We provide novel evidence on the time for which activities were performed and on the time periods when young adults were more sedentary and/or less active. With high sedentary time and low MVPA, young adults may be at risk for the life-course sequelae of these behaviours. [ABSTRACT FROM AUTHOR]

Background: Relatively little is known about the relations between dietary patterns and bone health in adolescence, which is a period of substantial bone mass accrual. Objectives: We derived dietary patterns that were hypothesized to be related to bone health on the basis of their protein, calcium, and potassium contents and investigated their prospective associations with bone mineral density (BMD), bone area, and bone mineral content (BMC) in a cohort of young adults. Design: The study included 1024 young adults born to mothers who were participating in the Western Australian Pregnancy Cohort (Raine) Study. Dietary information was obtained from food-frequency questionnaires at 14 and 17 y of age. Dietary patterns were characterized according to protein, calcium, and potassium intakes with the use of reduced-rank regression. BMD, bone area, and BMC were estimated with the use of a total body dual-energy X-ray absorptiometry scan at 20 y of age. Results: We identified 2 major dietary patterns. The first pattern was positively correlated with intakes of protein, calcium, and potassium and had high factor loadings for low-fat dairy products, whole grains, and vegetables. The second pattern was positively correlated with protein intake but negatively correlated with intakes of calcium and potassium and had high factor loadings for meat, poultry, fish, and eggs. After adjustment for anthropometric, sociodemographic, and lifestyle factors, a higher z score for the first pattern at 14 y of age was positively associated with BMD and BMC at 20 y of age [differences: 8.6 mg/cm² (95% CI: 3.0, 14.1 mg/cm²) and 21.9 g (95% CI: 6.5, 37.3 g), respectively, per SD increase in z score]. The z score for this same pattern at 17 y of age was not associated with bone outcomes at 20 y of age. The second pattern at 14 or 17 y of age was not associated with BMD, BMC, or bone area. Conclusions: A dietary pattern characterized by high intakes of protein, calcium, and potassium in midadolescence was associated with higher BMD and BMC at 20 y of age. Our results indicate that high consumption of low-fat dairy products, whole grains, and vegetables in adolescence are associated with beneficial effects on bone development. [ABSTRACT FROM AUTHOR]

Background. Active virtual reality gaming (AVG) may be useful for children with developmental coordination disorder (DCD) to practice motor skills if their movement patterns are of good quality while engaged in AVG. Objective. This study aimed to examine: (1) the quality of motor patterns of children with DCD participating in AVG by comparing them with children with typical development (TD) and (2) whether differences existed in the motor patterns utilized with 2 AVG types: Sony PlayStation 3 Move and Microsoft Xbox 360 Kinect. Design. This was a quasi-experimental, biomechanical laboratory-based study. Methods. Twenty-one children with DCD, aged 10 to 12 years, and 19 age- and sex-matched children with TD played a match of table tennis on each AVG type. Hand path, wrist angle, and elbow angle were recorded using a motion analysis system. Linear mixed-model analyses were used to determine differences between DCD and TD groups and Move and Kinect AVG type for forehands and backhands. Results. Children with DCD utilized a slower hand path speed (backhand mean difference [MD] = 1.20 m/s; 95% confidence interval [95% Cl] =0.41, 1.98); greater wrist extension (forehand MD=34.3°; 95% 0 = 22.6, 47.0); and greater elbow flexion (forehand MD=22.3°; 95% 0 = 7 .4 , 37.1) compared with children with TD when engaged in AVG. There also were differences in movement patterns utilized between AVG types. Limitations. Only simple kinematic measures were compared, and no data regarding movement outcome were assessed. Conclusions. If a therapeutic treatment goal is to promote movement quality in children with DCD, clinical judgment is required to select the most appropriate AVG type and determine whether movement quality is adequate for unsupervised practice. [ABSTRACT FROM AUTHOR]

Background. Back pain beliefs (BPBs) are an important modifiable factor related to disability associated with low back pain (LBP). Back pain beliefs have not been characterized in baby boomers, a group at risk for decreased activity levels and reduced productivity. Objective. The aims of this study were: (1) to identify factors related to BPBs and (2) to evaluate the association between LBP disability and beliefs. Design. A cross-sectional survey of community-dwelling baby boomers (born 1946-1964) was conducted. M ethods. Nine hundred fifty-eight baby boomers (mean age=56.2 years) participating in the Busselton Healthy Aging Study provided their history of LBP, BPBs, LBP behaviors related to care seeking (taking medication, seeking professional help) and activity modification (missing work, interference with normal activities, interference with recreational activities), LBP-related disability, and additional covariates with known associations with BPBs. Regression analyses were used to: (1) identify' factors associated with more positive beliefs and (2) test the association between more positive BPBs and lower LBP disability, independent of other correlates of BPBs. Results. More positive BPBs were associated with younger age, better mental well-being, and higher income, whereas more negative BPBs were associated with receiving sickness or disability benefits and the experience of LBP in the previous month. In participants who reported experiencing LBP within the previous month, more positive BPBs were associated with lower disability' scale scores and a decreased probability of interference with usual activities, independent of pain intensity, age, mental well-being, income, and employment status. Limitations. Cross-sectional analysis limits assessment of causality. Conclusions. Poorer BPBs were associated with greater disability. Characterization of the relationships between BPBs and LBP-associated behaviors and disability in baby boomers can assist in developing interventions to improve activity participation and productivity, potentially reducing the burden of LBP in this age group. [ABSTRACT FROM AUTHOR]

Office workers perform tasks using different information and communication technologies (ICT) involving various postures. Adequate variation in postures and muscle activity is generally believed to protect against musculoskeletal complaints, but insufficient information exists regarding the effect on postural variation of using different ICT. Thus, this study among office workers aimed to determine and compare postures and postural variation associated with using distinct types of ICT. Upper arm, head and trunk postures of 24 office workers were measured with the Physiometer® over a whole day in their natural work and away-from-work environments. Postural variation was quantified using two indices: APDF(90-10)and EVA(sd). Various ICT had different postural means and variation. Paper-based tasks had more non-neutral, yet also more variable postures. Electronics-based tasks had more neutral postures, with less postural variability. Tasks simultaneously using paper- and electronics-based ICT had least neutral and least variable postures. Tasks without ICT usually had the most posture variability. Interspersing tasks involving different ICT could increase overall exposure variation among office workers and may thus contribute to musculoskeletal risk reduction. Practitioner Summary:This study in office workers assessed posture variation, which is believed to protect against musculoskeletal complaints. Electronics-based tasks had more neutral upper body postures but less posture variation than other tasks. Combining tasks based on different technologies could increase postural variation in and outside the job for office workers. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to quantify and compare lumbar region kinetics in kick and flat serves performed by elite, adolescent male players with and without a history of low back pain (LBP). Lumbar region kinematics, as well as racquet velocity and the position of the ball at impact, was described to facilitate kinetic data interpretation. Methods: Twenty Tennis Australia adolescent male players participated; 7 had a history of disabling LBP and confirmed L4/L5 injury and 13 were age-, height-, mass-, and performance-matched controls. The VICON motion analysis system was used to record racquet, upper and lower limb, trunk, and lumbar movement during three "flat" and three "kick" serves. A customized mathematical model calculated lumbar region kinetics/kinematics, racquet velocity, and ball position at impact, and these are reported as if all players were right-handed. A series of 2 x 2 mixed-model ANOVA were used to compare between pain/no pain and kick/flat serves. Results: There was no significant difference in racquet velocity or ball position at impact between pain groups or serve types. The players with LBP reported significantly greater (mean difference = 1.5 N-kg~') peak left lateral force than the control group. The flat serve was associated with significantly greater flexion moments (mean difference = 2.7 Nkg~ ') than the kick serve. Conclusions: The lumbar region undergoes substantial loading during both the kick and the flat tennis serves, including lateral flexion forces approximately eight times those experienced during running. Given that these left lateral flexion forces are significantly greater in players with a history of disabling LBP and occur simultaneous with peak vertical force and extension and right lateral rotations, this may be an important LBP mechanism in this population. [ABSTRACT FROM AUTHOR]

Aim: To determine whether height, weight, body mass index (BMI) and chest width, as measured using portable tools, have adequate inter-tester reliability for use in field-based research. Methodology: Same-day repeated-measures inter-tester reliability study in 15 adolescent swimmers and three testers. Height was taken with a portable stadiometer and weight with a digital floor scale. BMI was calculated using weight in kilograms/height in metres squared. Chest width was measured at the level of the inferior border of the spinous process of T7 at the end of expiration, with an anthropometer. Major findings: The SEMs were 3.8 mm for height, 0.48 kg for weight, 0.22 kg/m2 for BMI and 12.8 mm for chest width. Intra-class coefficients (ICCs) for the anthropometric variables were all above 0.98, except for chest width (0.80). Significant differences between testers for height and chest width existed, but not for weight and BMI. Conclusions: Anthropometric measures that are measured using field-based tools have acceptable inter-tester reliability for use in field-based assessment. [ABSTRACT FROM AUTHOR]

Background. Disability in adults with low back pain (LBP) is associated with negative back pain beliefs (BPBs). Adult BPBs can be positively influenced with education, resulting in reduced LBP disability. By late adolescence, the prevalence of LBP reaches adult levels. The relationship among LBP experience, LBP impact, and BPBs has not been investigated in late adolescence. Objective. The aim of this study was to document unknown relationships among LBP experience, LBP impact, and BPBs in 17-year-olds. Design. A cross-sectional study design was used. Methods. Adolescents (n= 1,126) in the Raine Study provided full information on LBP, LBP impact (sought professional advice or treatment, taken medication, missed school or work, interfered with normal activities, interfered with physical activities), BPBs, and a number of covariates. Results. Back pain beliefs were more positive in participants with experience of LBP (X=30.2, SD=5.6) than in those without experience of LBP (X=28.5, SD=5.1). Individuals with LBP without activity modification impacts had more positive BPBs than those with activity modification impacts, even after adjustment for mental well-being and sex. The adjusted difference in BPBs between participants with experience of LBP but no activity modification impacts and those reporting all 3 activity modification impacts was 2.9 points (95% confidence interval=1.7 to 4.2). Participants with no activity modification impacts had more positive BPBs than those with no experience of LBP (adjusted difference=2.2 points, 95% confidence interval 1.4 to 2.9). More positive BPBs also were associated with female sex, lower body mass index, higher family income, better 36-Item Short-Form Health Survey (SF-36) Mental Health scale scores, and more positive primary caregiver beliefs. Limitations. Cause and effect cannot be ascertained with the cross-sectional design. Conclusion. Differences in BPBs are associated with different levels of LBP impact at 17 years of age. This finding provides a potential target for intervention early during the life course. [ABSTRACT FROM AUTHOR]

Background. Conflicting evidence exists regarding relationships among sitting posture, factors that influence sitting posture, and back pain. This conflicting evidence may partially be due to the presence of multiple and overlapping factors associated with both sitting posture and back pain.Objective. The purpose of this study was to determine whether the degree ofslump in sitting was associated with sex and other physical, lifestyle, or psychosocial factors. Additionally, the relationship between the report of back pain made worse by sitting and the degree of slump in sitting and other physical, lifestyle, or psychosocial factors was investigated. Design. This was a cross-sectional study. Methods. Adolescents (n1,596) completed questionnaires to determine lifestyle and psychosocial profiles and the experience of back pain. Sagittal sitting posture, body mass index (BMI), and back muscle endurance (BME) were recorded. Standing posture subgroup categorization was determined. Results. Multivariate analysis revealed that the most significant factor associated with the degree of slump in sitting was male sex, followed by non-neutral standing postures, lower perceived self-efficacy, lower BME, greater television use, and higher BMI. Multivariable analysis indicated poorer Child Behaviour Checklist scores were the strongest correlate of report of back pain made worse by sitting, whereas degree of slump in sitting, female sex, and BME were more weakly related. Limitations. Causality cannot be determined from this cross-sectional study, and 60% of sitting posture variation was not explained by the measured variables. Conclusions. Slump in sitting was associated with physical correlates, as well as sex, lifestyle, and psychosocial factors, highlighting the complex, multidimensional nature of usual sitting posture in adolescents. Additionally, this study demonstrated that a greater degree of slump in sitting was only weakly associated with adolescent back pain made worse by sitting after adjustment for other physical and psychosocial factors. [ABSTRACT FROM AUTHOR]

Purpose: Sitting at work can be associated with musculoskeletal pain, but the effect of reductions in sitting is not well understood.We examined relationships with musculoskeletal pain of changes in sitting, standing, stepping, and short and long bouts of these behaviors. Methods: Analyses pooled data from 224 desk workers (68.4%women;mean ± SD age = 45.5 ± 9.4 yr; body mass index = 28.1 ± 6.1 kgm-2) in intervention trial.Device-assessed (activPAL3) sitting, standing, and stepping time andmultisite musculoskeletal pain (Nordic Questionnaire; 12 body areas) were assessed at baseline, 3months, and 12 months. Compositional data analyses in linear mixed-effects regressions examined relationships within 16 waking hours of the behaviors and their short and long bouts, with changes from baseline in acute and chronic multisite musculoskeletal pain at 3 and 12 months. Analyses were adjusted for initial group randomization and relevant covariates. Results: At 3 months, increased standing relative to changes in other compositions was significantly associated with increased multisite musculoskeletal pain (acute: β = 1.54, 95% confidence interval [CI] = 0.10 to 2.98; chronic: β = 1.49, 95% CI = 0.12 to 2.83). By contrast, increased stepping relative to changes in other compositions was significantly associated with reduced multisite musculoskeletal pain (acute: β = -1.49, 95% CI = -2.97 to -0.02; chronic: β = -1.87, 95% CI = -3.75 to -0.01). Neither sitting reduction relative to changes in other compositions nor changes in short bouts relative to long bouts of the behaviors were significantly associated with multisite musculoskeletal pain changes. At 12months, there were no significant associations for any of the compositional changes. Conclusions: In the short term, while increasing standing with reduced sitting time can be unfavorable, concurrently increasing stepping could potentially reducemusculoskeletal pain. In the longer term, musculoskeletal painmay not be increased by moderate reductions in sitting time through spending more time standing or stepping. [ABSTRACT FROM AUTHOR]

Purpose: This study compared regional lumbar (upper and lower), pelvis, trunk, and lower limb kinematics between elite male adolescent players with and without a history of low back pain (LBP) during the kick and flat serves as well as regional lumbar mobility and serving kinematics relative to the end of range. Methods: Seven players with a history of LBP and confirmed L4/L5 injury and 13 controls matched for age, height, mass, and performance underwent a three-dimensional motion analysis during serving trials and lumbar mobility assessments. Regional lumbar, pelvis, trunk, and lower limb kinematics were compared between pain/no pain and kick/flat serves using a series of 2 x 2 mixed- model ANOVA, with independent samples Wests used to compare regional lumbar mobility between pain/no pain. Results: The pain group had significantly reduced lower lumbar mobility in every plane of motion than the no pain group. The pain group demonstrated less right lower lumbar and pelvis/shoulder rotation, greater right pelvic tilt, earlier peak right knee extension velocity during the drive phase of the tennis serves, and greater lower lumbar and pelvis left rotation, upper lumbar left lateral flexion, and anterior pelvis tilt during the forward-swing phase. All players approached their lumbar end of range during the serve. Conclusions: The results of this investigation suggest that a multidimensional LBP management and prevention strategy is required, including the assessment of regional spinal mobility, the lower limb and upper limb and spinal kinematics, and the integrated work between clinicians and coaches to adapt adverse technique [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to identify unique organized sport trajectories from early childhood to late adolescence in an Australian pregnancy cohort, the Raine Study. Methods: Participation in organized sport was assessed at ages 5, 8, 10,14, and 17 yr. Physical activity, body composition, and self-rated physical and mental health were assessed at the age of 20 yr. Latent class analysis was used to identify patterns of sport participation. To assess the internal validity of the trajectory classes, differences in health characteristics between trajectories were analyzed using generalized linear models. Results: For girls, three trajectory classes were identified: consistent sport participators (47.5%), sport dropouts (34.3%), and sport nonparticipators (18.1%). For boys, three trajectory classes were identified: consistent sport participators (55.2%), sport dropouts (36.9%), and sport joiners (8.1%). For girls, there were overall differences across trajectory classes in lean body mass (P = 0.003), lean mass index (P = 0.06), and physical health (P = 0.004). For boys, there were differences across classes in physical activity (P = 0.018), percent body fat (P = 0.002), lean body mass (P < 0.001), lean mass index (P < 0.001), physical health (P = 0.06), and depression scores (P = 0.27). Conclusion: This study identified unique, sex-specific trajectories of organized sport participation. The differences in health outcomes between trajectory classes, such as participants with consistent sport participation having more preferable health outcomes at the age of 20 yr, support the internal validity of the trajectories. Strategies are needed to identify and encourage those in the dropout trajectory to maintain their participation and those in the nonparticipator or joiner trajectories to join sport earlier. Specifically, interventions to encourage early sport participation in girls and help nonparticipating boys to join sport during adolescence may help more children receive the benefits of sport participation. [ABSTRACT FROM AUTHOR]